Controlling Thermal Expansion with Lattice Structures Using Laser Powder Bed Fusion

Tuning the Co-efficient of Thermal Expansion (CTE) of a component is traditionally limited by material choice. Laser Powder Bed Fusion (LPBF) enables the designer to create complex geometries including lattice structures. When combined with a secondary material, these metallic lattice structures can be designed to exhibit different CTE’s whilst retaining stiffness. This allows the designer the freedom to adjust the CTE by changing CAD variables such as lattice angle, and member thicknesses. This paper aims to develop an arrangement for CTE matched components for high precision optical systems. Development pursued using a Static Thermo-Structural Finite Element Analysis model to determine the best arrangements for the required CTE change. The results are incorporated into a new design prototype of a full cylindrical lens system in metal on a Laser Powder Bed Fusion machine.